Scale Lens Demo

Info

Overview

Confocal and Multiphoton Imaging Core will host a demonstration of the Scale lens from Carl Zeiss. This LD Plan-Apochromat 20x/1.0 lens with working distance of 5.6 mm allows to carry out imaging of a whole brain cleared with the Scale technique, published last year in Nature Neuroscience by the group of Dr. Artsushi Miyawaki, Brain Research Institute, RIKEN, Japan. The lens is installed on the Zeiss 7MP Multiphoton Microscope in Rm. 8122. In Scale-treated mouse brain, neurons labeled with genetically encoded fluorescent proteins were visualized at an unprecedented depth in millimeter-scale networks and at subcellular resolution. The improved depth and scale of imaging permitted comprehensive three-dimensional reconstructions of cortical, callosal and hippocampal projections whose extent was limited only by the working distance of the objective lenses.

On the image below: a. A three-dimensional reconstruction of YFP-expressing neurons in 16 (8 × 2) quadratic prisms located in the cerebral cortex and hippocampus is shown in b. A high-magnification xy image at a depth of 0.9 mm (a yellow box in b) is shown in c. (Image taken from Hama et al., Nat. Neurosci. 2011)

Why Scale?

Scattering is the major problem limiting light penetration into live tissues. Optical clearing allows to achieve refractive uniformity, leading to the reduction in scattering. Several clearing techniques have been developed earlier, of which benzyl benzoate/benzyl acolohol (BBA) allowed to achieve high level clearing, however, at the expense of significant quenching of fluorescent labels. Scale technique, based on urea, is claimed not to affect labels' quantum yield. Although an increase in brain size is observed at Scale application (BBA causes shrinking), relative positions of internal structures (hippocampus, amygdala and white matter) maintained their overall shape and proportions.

Lens specs

Magnification

20x

Numerical Aperture

1.0

Parfocal length

85 mm

Overall length

105 mm

Working Distance

5.6 mm VIS-IR

Apochromatic correction of the longitudinal chromatic aberration for the wavelength range